The liquid crystal displays possess many merits of small volume, low power consumption and irradiation free and have been widely used, such as in the liquid crystal TV, smart phone screen, tablet computer or computer screen, and dominates the flat panel display field.
Now, the requirements for the display results of the liquid crystal displays become higher and higher. The products of high resolution, high color gamut, high contrast, high refresh rate become popular. With the introduction of these technologies, the power consumption of the liquid crystal display gets higher and higher. Particularly, in the state of high resolution, the over large current of some specific image can result in the over large power consumption. Consequently, the temperature of the liquid crystal display is too high and cannot normally work.